Steam generator



AUGUST-THEODOR HERPEN STEAM GENERATOR Filed March 2, 1927 5 Sheets-Sheet l lml c I 1 VENTOR AUjUST Theoc zor Hey-fen. WY

ATTORNEYS Aug. 30, 1932.

AUGUST-THEODOR HERPEN STEAM GENERATOR Filed March 2. 1927 5 Sheets-Sheet 2 #%a if? oooooooflvmvwowwwo 00000000000 0 AU vsmaowsi m 1932- AUGUST-THEODOR HERPEN 1,874,527

STEAM GEXERATOR Filed March 2, 192"! 5 Sheets-Sheet 3 A ORNEYS 1932- AUGUST-THEODOR HERPEN 1,874,527 I STEAM GENERATOR Filed Maih 2, 1927 5 sheets-sheet 4 I 2 efi l/i/ A ORNEYS 30, 1932- Y AUGUST-THEODOR HERPEN 1,374,527

STEAM GENERATOR Filed March 2, 1927 5 Sheets-sheaf 5 g 7 Al U l l Patented Aug, 30, 1932 UNITED STATES PATENT OFFICE aceusr-rnnonoa HERPEN, or LEIPZIG, Guam, ASSIGNOR :ro LA mom qonrona- TION, A coaroaa'rronor NEW YORK srmm eannna'ron Application filed March 2, 1927, Serial No. 172,032, and in Germany Kai-ch 6, 1920.

This invention relates to steam generators of the type in which the fluidto be converted into steam is carried in continuous circulation successively through the heat exchanger in which a part of the fluid is converted into steam and through a steam separator in which the steam is separated from the unvaporized fluid, the unvaporized fluid being then returned to the heat exchanger.

In those steam generators which have a defined path of circulatiomthat is, a continuous closed circuit through which the fluid is supposed to move in order to return to its starting point, a substantial circulation movement results from the'difi'ere'nce in weight between the-descending colder fluid and the warmer fluid permeated with steam bubbles. In some recent commercial constructions the circulation movement has been brought about by mechanical means such, for example, as rotary pumps or injectors.

The present invention aims so to improve steam generators of thetype hereinabove set forth, which do not have mechanical means for producing the circulation movement that such generators will have an intensifie circulation whereby higher temperatures than are practicable in generators of ordinary construction may be employed without danger of injury to the heat exchanging tubes.

Experience has shown that with the ordinary water tube boilers, particularly those with vertical or steeply'inclined tubes for insuring circulation and wlich comprise usually smooth heat exchanging tubes of comparatively large diameter in orderto insure minimum resistance to the flowing water, the natural water circulation is not suflicient, when high heats are used, to protect thetubes from burning through.

In that type of boilers in which the tube systems frequently change directions, especi ally those with relatively long tubes of relatively small diameter, the natural fluid circulation is far from sutficient to prevent local overheating of the tubes. As above suggested, to overcome this tendency to burning out, means have been provided in recent times for mechanically insuring the circulation of the water.

The present invention aims particularly to provide a very simple solution of the problem of insuring the desired rapidity and continuity of the fluid circulation, without utilization of mechanical means for this purpose, even in systems in which, because of the length, change in direction or small diameter, or any combination of these characteristics, the tube system serving as a steamgenerator ofl'ers comparatively great resistco ance to the flow of the fluid therethrough.

Other objects and important features of the invention will appear from the following description and claims when considered in connection with the accompanyng drawings, in which Figure 1 is a view illustrating the application of the invention to a steam generator of the type in which groups of tubes are connected to upper and lower headers;

Figure 2 shows the invention embodied in a steam generator in which the distributing headers and the collecting headers are brought into proximity to each other' by bending the generator tubes through an angle of substantially 180.

Figure 3 illustrates a non-clogging throttling arrangement that may be employed in connection with the invention to insure the desired direction of circulation of the fluid 30 through the system; f

Figure 4 is a vertical section through a steam generator in which substantially all, of the elements of the invention are enclosed within the stack-like extension of the heat chamber;

Figure 5 is a horizontal section the upper part of Figure 4;

through;

igure 6 is a vertical section through still another embodiment of the invention, which 1 includes a system of tubes forming substantially a water wall for the heat chamber;

Figure 7 is a horizontal section near the upper end of Figure 6;

Figure 8 is a vertical section through the steam generator shown in Figures 6 and 7 in a plane at rightangles to the plane shown in F1gure 6, and

Figure 9 IS a perspective detail showing distributing headers-4 and upper collecting headers 6, there preferably being several of the tube groups thus formed in a single installation, the lower headers 4 being connected to distributing tubes 5 and the upper headers 6 being connected to collecting tubes 7 and from the upper collecting tubes 7 riser tubes 8, the number of which is lessand the diameter of which is greater than the numher and diameter of the generator tubes 2, extend to a steam separator 10, theseparator 10 being located much higher than is required by the boiler construction itself, thereby providing a relatively extended rising travel of the mixture of steam and water originating in the generator tubes 2.

It will be seen from an inspection of Figure 1 of the drawings that the generator tubes 2 may be comparatively long and of comparatively small diameter and that they may extend substantially vertically into the stack- 7 like extension 14 of the heat chamber 12 in which the lower headers 4 and the distribut' .in tubes 5 are shown as arranged, the tubes being preferably spread somewhat at their lower ends to permit the ready ingress of the heated gases into the channels between the tubes. The riser pipes relatively high placing of the separator 10,

'are'also comparatiyely long, for a purpose hereinafter more specifically set forth.

From the lower end of the separator 10, the return pipe or pipes 16 carry the separated water to the lower distributing tubes 5 of the tube groups. I c

It will be seen that the higher the riser pipe or pipes 8 connecting the collecting tubes '7 with the separator 10 extend, the greater becomes the total heights and therefore the difference in weight of the fluid columns in the descending tube or tubes 16 on the one hand and of the columns of the mixture of fluid and vapor bubbles in the riser tube or tubes 8 together with the generator tubes 2 on the other hand. It will further be seen that the riser tubes 8 are of comparatively large diameter and that they extend to a comparatively high point above the generator and therefore that the utilization of a number of these riser tubes less than the number of 8, by reason of the generating tubes, through which riser tubes the entire mass of water and steam streams,. in combination with a highly elevated steam separator affords improved and novel means for maintaining a fluid circulation force of the desired intensity by reason of the markedly increased difl'erential between the two sides of the system and the insurance against a force produced by the marked difference in gravity between the two sides of the system, thatis, between the riser side, including the generator tubes 2 and the comparatively long riser pipes their large diameter the mixture of steam and water is free to flow rapidly, and the falling side of the system, including the descending tubes 16, is further increased by providing means for checking .counterfiow such as a check valve 18 located,.for example, in the down pipe 16, or choking or restricting means, such as are employed in other arts, which, while not positively closing the passage for the circulating water, tend to resist counterfiow. As shown in Figure 3 of the drawings,- for example, such choking or restricting means may comprise centrally perforated baffle plates or orifices 20 arranged one be hind the other at the entrance to the genera-v tor tubes 2. The advantage of arranging a serles of these bafiie plates one behind the other is thatthe same choking-effect may be 8, through which by reason of r obtained with a larger opening 22 in each plate than could be obtained with a single plate havifig the same opening, thus permittin the provision of a larger opening 22 less liable to be clogged by foreign material in the water.

In Figure 2 of the drawings, the distributing tubes 5 and headers 4 for the generator tubes 2 are shown as located in the stack-like portion 14 of the heat ch amber, the tubes 2 the steam separator only one direction of flow is permissible, that means he provided for starting the water circulation in the desired direction. As an example of means for starting'the circulation in the right direction, steam may be blown into the riser pipe or ipes 8 through a tube 24 until the circulatlon is established, and then shut off.

locatedin the hottest In the form of the invention shown in Figures 4 and 5 of the drawings, the generator tubes .2 are'connected at their lower ends through headers (not shown) to distributing tubes 5, and at their upper ends through similar headers (not shown) to collecting tubes 7 Connected to the distributing tubes 5 and extending at .about right angles to.

said tubes are the fall tubes 16, and connected to the collecting tubes 7 and likewise extending at about right angles thereto are the riser tubes 8,these tubes being preferably so arranged, as shown in Figure 5, that they. form tube Walls in the stack-like portion 14 of the heat chamber, the fall tubes being preferably on the outer sides of these walls so that the riser tubes are more exposed to the heat of the gases that have passed over the generator tubes 2 than are the fall tubes 16. The space 26 between the walls formed by the riser and fall pipes in the stack 14 may serve for the reception of an economizer, an air heater or any other heat exchange device not shown. I

Both the riser pipes 8 and the descending pipes 16 open at their upper ends into the steam separators 10, the riser pipes preferably extending nearer the water level in the steam separators 10 than the fall pipes. As shown, the riser pipes 8 extend nearly to the water level in the separators 10. The separated steam is conducted away from the separatorslO through the pipe 28, the two pipes 28 from the respective separators shown in Figure 4 preferably discharging into a common steam main 30.

Tn Figures 6 to 8 inclusive is illustrated somewhat diagrammatically a further modie fied embodiment of the invention. This embodiment of the invention is similar to that shown in Figure 4 with respect to the fact that the riser and fall tubes 8 and 16 are so arranged that they form tube walls in the stack. In this form of the invention, however, the riser and fall tubes 8 and 16 are shown side by side in the respective tube walls instead of being arranged with the fall pipes'behind the riser pipes as in the embodi- "ment illustrated in Figures 4 and 5. The

steam separators are also similar to those shown in Figure 4.

The embodiment of the invention shown in Figures 6 to 8 inclusive preferably includes both a radiant heat generator and a convective heat generator, the two generators working in parallel. The radiant heat generator comprises generating tubes 32 which open below into distributing tubes 34 and above into collecting tubes 36, these generator tubes 32 being so arranged that they form both the cover and a part or a whole of the side walls of the combustion chamber or heat chamber 12 of the boiler. The boiler water is conducted to the distributing tubes 34 by means of two fall tubes 38. .The steam and water mixture originating 1n the tubes 32 is conducted away from the collector 36 by means of the riser tubes 40. V

The convectiveheat generator comprises generator tubes 2 bent through 180 and opening at their ends into vertically offset headers 4 and 6. As shown in Figure 8, theheaders 4 and 6 are connected respectively to corresponding part of the weight of the generator tubes 2, is transferred to the distributors 5 through the connecting tubes 42.

The steam and water mixture formed in the generator tubes 2 passes into the headers 6 (see,Figures 4, 6 andl8). The headers 6 are connected with the riser tubes 8 in a manner corresponding to the manner of coirnection of the headers 4 with the fall tubes 16. The steam and water mixture is therefore conducted through the connecting tubes 44 to the collectors 7 which at their ends discharge into riser pipes or tubes 8.

The collectors 7 and the distributors 5 lie in two different planes, as may be seen from Figure 8, in order to permit the combustihn gases to have'as unobstructed a passage as possible. a

The collectors 7 are firmly supported at their two ends and thus transfer their own weight and the weight of the riser tubes 8,

and of the generator, to the housing.

The assembled riser tubes 8 and 40, as well as the fall tubes 16 and 38, are so arranged, according to the invention, that they form walls of the boiler stack (see Figure 7 They all open at their upper ends into a steam separator 10formed as a tube of large diameter, the construction of which is more fully described in connection with Figure 4.

In the separators 10 are located baffles 46 which cause the steam discharge to take place at the ends of the separators where no riser pipes discharge into the separator and where, therefore, a more undisturbed condition of the water is to beexpected. The separators are for this purpose extended somewhat beyondthe width of the cross-section of the stack. 8

As above pointed out in connection with Figure 4, the steam discharge takes place through the conduits 28 which unite in the steam main 30.

The weight of the separators 10 is transferred by the riser pipes 8 and thefall pipes 16 to the collectors 7 and the distributors and thereby to the housing.

The weight of the riser pipes 40 and therewith also the weight of the collectors 36 and a part of the weight of the generator tubes scribed. As in the form of the invention shown in Figure 4, the space in the stack between the walls formed by the riser and fall tubes can serve for the reception of'an economizer, air heater or other heat exchanger, not shown.

The steam separators 10 are enclosed within a common housing 50, which is placed upon the housing 14 of the stack.

For the production of the most favorable draft, suction devices 52, provided with nozzles or spray devices 54;, can be hung between the separators 10, these suction devices being rigidly connected with the housing 5() to avoid disturbance by the heat extensions of the separators 10 with which they have no connection. 1

The steam separators 10 may be connected with each other by connecting tubes, not shown in the drawings, for better equalization of the water level and for insuring their reciprocal status.

The number of separators 10, of which two i only are illustrated in the drawings, can, of

course, be varied at will. With smaller units a single separator is usually sufiicient. With very large units the number could be increased to four.

What is claimed as new is:

1. A steam generator comprising, in combination, a group of relatively long tubesof relatively small diameter, a distributing header connected to one end of the roup of tubes, a collecting header at tie other end of said group, .a steam and water separator located at a height above said collecting header, a riser pipe substantially inclined to the horizontal connecting said collecting header with said separator, and a down or return pipe connecting the water space in said separator with said distributing header,,whereby the difierence in the weight of the water in the down pipe and of the steamand any water in the riser pipe tends to produce circulation of water through the system, said steam and water separator being positioned much higher than is required to produce unrestricted circulation through said system, said distributing header being provided with means for restricting the flow of water into the various tubes whereby a head of water is required to produce flow of water throu said restricting means into the tube, the extra height of said separator above the tube providing said head of water as well as r to produce flow through the system.

Steam generator comprising a plural- '.and any water in the at their upper ends to the water space of the chambenand connected at their other ends to. the tubes at the other end thereof,the arrangement being such that the difference in weight of the columns respectively of steam and any water in the riser pipe and of water in the down pipe is utilized to effect the movement of the water from the water space of the chamber through the tubes, said riser and down pipes being arranged to form at least two walls of a stack-like space within the combustion gas passage of sufficient height and cross sectional area to serve for the reception of a heat exchanger.

3. Steam generator comprising a plurality of steam generating tubes connected in paral-' lel, a chamber located above the tubes and providing a water space and a space for separation of steam and water discharged from the tubes, a riser pipe substantially inclined to the horizontal and connected at its upper end to said chamber in such a way as to cause the steam and water to be separated in said chamber and connected at its other end to the tubes at one end thereof, a down pipe connected at its upper end to the'water space of the chamber and connected at its other end to the tubes at the other ends thereof, the arrangement being such that the difference in weight of the columns respectively of steam riser pipe and of water in the down pipe is utilized to efiect the movement of the water from the water space of the chamber through the tubes, certain of said steam generating tubes being arranged for absorption of heat by convection and certain other of said tubes being arranged for absorption of radiant heat, said tubes for absorption of radiant heat being arranged to protect the walls of the combustion chamber.

4. Steam generator comprising a plurality of steam generating tubes connected in parallel, a chamber located above the tubes and providing a water space and a space for separation of'stearn and water discharged from the tubes, a riser pipe substantially inclined to the horizontal and connected at its upper end to said chamber in such a way as to cause the steam and water to be separated in said arrangement being such that the difierence in weight of the columns respectively of steam and any water in the riser pipe and of water in the down pipe is utilized to efiect the movement of the water from the water space of the chamber through the tubes, said tubes be ing connected between headers and said steam and water separating chamber being supported by the pipes connecting said chamber to said headers, which pipes in turn are supported by said headers.

5. A; single pass tower-like water tube boiler which comprises a wall of tubes arranged'in tower-like manner over and around the combustionchamber, the walls of said chamber being protected by said tubes and being shaped so as to form a combustion chamber having reduced cross section near its top and a gas passage above the combustion chamber and of smaller cross section than the combustion chamber, additional substantially vertical tubes substantially uniformly distributed throughout the-cross section of said gas passage, headers connecting the tubes in the combustion chamber, separate headers connecting the tubes in said gas passage, a steam separator rhuch higher than the highest part of said tubes, riser and fall pipes connecting the headers for tubes in the combustion chamber to said separator and separate riser and fall pipes connecting the headers for tubes in the gas passage to said separator. I

6. A boiler as defined in claim 5, in which the fall pipes to the combustion chamber pass through the gas passage nearer its walls than do the riser pipes. 1

7t A boiler as defined in claim 5, in which the fall pi es pass through the combustion chamber 0 ose to its walls and behind the boiler tubes. i

8. A boiler as defined in'claim 5, in which the. riser and fall pipes pass substantially vertically through said gas passage above the boiler tubes a height comparable to that 00- cupied by the boiler tubes in thegas passage.

9. A boiler as defined in claim 5, in which the riser and fall pipes pass substantially vertically through said gas passage above the boiler tubes a height comparable to that occupied by the boiler tubes in the gas passage and are arranged so as to form a space between groups of said riser and fall pipes which is utilized for a heat exchanger to further absorb heat from the gases.

' 10. A boiler as defined in claim 5, in which the riser and fall pipes pass substantially vertically through said gas passage above the boiler tubes a height comparable to that occupied by the boiler tubes in the gas passage and are arranged along the walls thereof so as to form a space between groups of said riser and fall pipes which is utilized for a heat economizer heat exchanger, and the separator is positioned in said gas passage.

in said chamber and connected at its other end to the tubes at one end thereof, a down pipe connected at its upper end to the water space of the chamber and connected at its other end to the tubes at the other ends thereof, the arrangement being such that the difference in weight of the columns respectively" of steam and any water in the riser pipe and of water in the down pipe tends to eiiect the movement of water from the water space of the chamber through the tubes, and orifices at the ends of the tubes connected to the down pipe for restricting the flow of water into the tubes, said chamber being located at a height substantially above that required for flow through tubes without orifices such that the difference in weight of the columnsof water in the riser ipe and in the down pipe provides also a ow impelling pressure upon the orifices to produce movement of water into the tubes through said orifices.

12. A steam generator according to claim 11, in which a series of orifice devices one beseries of orifices.

13. A. steam generator according to claim 11, having means for reducing the weight of the column in the riser pipe to initiate the circulation of the water inthe desired direction through the circuit.

14. Steam generator comprising a plurality of steam generating tubes connected in, parallel, a chamber located above the tubes and providing a Water space and a space for separation of steam and water discharged fromthe tubes, a riser pipe substantially inclined to the horizontal and connected at its upper end to said chamber in such a way as to cause the steam and water to be separated in said chamber and connected at its other end to the tubes at one end thereof, a down? pipe connected at its upper end to the'water space of the chamber and connected at its other end to the tubes at the otherv end thereof, the arrangement being '7 from the tubes,

1 end to the tubes at one end thereof, a

85 tube, said tube being 4 water space and a s water in the riser .ity of steam generating tubes connected in through the tubes, said steam and water separating the chamber being supported by the pipzs connecting said chamber with the tu s.

15. Steam generator comprising a plurality of steam generating tubes connected in parallel, a chamber located above the tubes and providin a water space and a space for separation of steam and water discharged a riser pipe substantially inclined to the horizontal and connected at its upper end to said chamber in such a way as to cause the steam and water to be separated in said chamber'and connected at its other down pipe connected at its upper end to the water space of the chamber and connected at its other end to the tubes at the other end thereof, the arrangement being such that the dif- 20 ference in weight of the columns respectively of steam and any water in the riser pipe and of water in the down pipe is utilized to effect the movement of the water from the water space of the chamber through the tubes, said 25 tubes being connected to headers in offset arrangement, said headers being connected by means of pipes of different lengths to cross headers to which the riser and down pipes are connected. 1 16. Steam generator comprising a steam generating tube connected at-its ends respectively to a riser pipe receiving steam and any water delivered therewith from the tube and to. a. down pipe for delivery of water to the provided with means for restricting the amount of the water entering and flowin through the tube, the ends of the riser and own pipes remote from the tube being'connected to a chamber providing a ace for separation of steam and water, sai at such a height above the tube that the difference between the. column of water in the down pipe and the column of steam and any ipe is sufiicient not only to produce convection circulation of the water through the tube but also to overcome the ,resistance offered by said restricting means and to deliver said water therethrough. 17. Steam generator comprising a pluralparallel between .a riser pipe and a down pipe, said riser pipe being arran ed to receive from the tubes the steam an any water delivered therewith and said down pipe being arranged for delivery of water to the tubes, said tubes at the ends the wateris delivered being provided with devices forming restricting orifices through 50 which the water is distributed to the tubes,

the ends of the riser and down pipes remote from the tubes being connected to a chamber providing a water space and a space for separation of steam and water, the arrangement being such that the generation of the steam chamber being located in the tubes tends b convection action to producecirculation 0 water from the chamber through the down pipe and through the tubes and through the riser pipe toward the chamber, said chamber being located at a height above the tubes greaterthan that required to provide the difference in the columns of water in the'down pipe and of steam and any water in the tubes and in theriser pipe for producing such convection circulation, sa d extra height being that required to cause the 20w of water into the tubes through said orices.

18. The process of producing circulation of water in a steam generator having a steam generating tube which forms part of the water circulating system of the generator which comprises creating a resistance to the flow of water at the entrance to said tube, applying to said end of the tube a pressure due to a column of the water within the system, applying to the other end of said tube a column within the system of steam and any water mixed therewith v as discharged from said tube, said columns being of like extent of height, said height being such that the difference in pressure created by said columns is effective not "only to cause fiow of water through the tube by convection but also to overcome the resistance to flow of water into the tube created at the entrance to the tube.

19. The process as defined in claim 18, which further comprises initiating a flow in the desired direction by a circulating means.

20. Process of producing flow of water through a steam generating tube against the resistance opposing said flow, which consists in applying a pressure to one end of the tube due to a column of water of substantial height, and maintaining upon the outlet end of the tube 'a pressure substantially less than that applied to the said inlet end bydischarging from the outlet end of the tube the steam and any water mixed therewith against a column of steam'and any water mixed therewith of like extent of height to that of said water column, whereby the difference in pressure due to the two said columns exterior of the tube produces the pressure to overcome said fldw opposing resistance, the column of steam and any water mixed therewith being surrounded with material at least as hot as the water va or in said column.

Signed at ewYork, N. Y., this 1st day of March, 1927.

AUGUST-THEODOR HERPEN.

thereof to which I 

